TM 9-759 WAR DEPARTMENT TECHNICAL MANUAL MEDIUM TANK M4A3 (FORD) AUGUST 4, 1942 The medium tank M4A3 is an armored, full track-laying vehicle, powered by a 500 hp Ford tank engine which is an eight cylinder, liquid cooled, "V" type engine designed specifically for tanks. The engine is located in the rear of the hull. The operator steers the vehicle by means of two levers located in the front end of the hull. The vehicle has five forward speeds and one reverse. The tank is wired for radio installation, and for an interphone system within the tank.